US Pharm. 2006;6:18.     

Long-Term Estrogen Therapy May Be Linked to Breast Cancer Risk
An article in the Archives of Internal Medicine reports a possible relationship between long-term estrogen therapy use and a higher risk of breast cancer among postmenopausal women. Results from the Women's Health Initiative (WHI) found no significant link between estrogen therapy and breast cancer in women who took the hormone for seven years.

Over the past 30 years, researchers at Brigham and Women's Hospital and Dana Farber Cancer Institute in Boston evaluated some 30,000 women from the Nurses' Health Study who were postmenopausal and had had a hysterectomy. Throughout the study period, 934 invasive breast cancers developed, 226 among women who had never used hormones and 708 among women who were using estrogen at the time. The study revealed that the longer a woman used estrogen, the higher her risk of breast cancer. The risk factor increased in those women who had been taking estrogen for more than 20 years.

"Although current use of estrogen therapy for less than 10 years was not associated with a statistically significant increase of breast cancer risk, the WHI has shown an increased risk of stroke and deep-vein thrombosis in the same period," concluded the researchers. (Arch Intern Med. 2006;166:1027-1032)

Beware of Mixing Chamomile and Warfarin
According to a report in the Canadian Medical Association Journal, Canadian doctors are warning that the combination of chamomile and warfarin may be deadly. Drs. Robert Segal and Louise Pilote at McGill University Health Centre in Montreal cite a case of a 70-year-old woman on warfarin who developed severe internal bleeding after drinking chamo­ mile tea. According to the report, while warfarin is already known to interact with garlic, onion, and ginger, this is believed to be the first documented case between chamomile and the blood-thinning drug.

Patients should "make their physicians and pharmacists aware of what herbal products they consume so that potentially harmful interactions can be identified," said Dr. Pilote. 

Corticosteroid Treatment May Be Linked to Atrial Fibrillation
High doses of cortico­ steroids may lead to an increased risk of atrial fibrillation, an irregular heartbeat that occurs when the upper two chambers of the heart contract irregularly. Patients who exhibit atrial fibrillation are at four to five times greater risk for a stroke or other cardiovascular complications.

According to a study published in the Archives of Internal Medicine, researchers at Erasmus University in Rotterdam, the Netherlands, followed nearly 8,000 adults 55 years of age or older for 10 years or until they developed atrial fibrillation or died. Patients who received high doses of cortico­ steroids to treat other disorders such as asthma, arthritis, allergies, or blood cancer were six times more at risk for atrial fibrillation.

The researchers said that corticosteroids could affect heart function by upsetting the balance of potassium in the heart muscle cells or they may retain sodium and fluids, which can lead to high blood pressure, congestive heart failure, or enlarged atria. (Arch Intern Med. 2006;166:1016-1020)

New Drug Treats Bone Marrow Disorders
The FDA has approved a new injectable drug to treat myelodysplastic syndrome (MDS), a disease in which the cells in a person's bone marrow do not function properly. Bone marrow contains stem cells that grow into white blood cells, red blood cells, and platelets. A patient with MDS cannot produce enough normal blood cells and/or the cells die prematurely, a condition that often develops into acute myeloid leukemia (AML), an aggressive type of cancer.

Dacogen (decitabine), manufactured by MGI Pharma, will treat the 7,000 to 12,000 cases of MDS diagnosed each year in the United States. According to clinical trials, 17% of MDS patients treated with decitabine realized an anticancer response. While the average duration of time to cancer progression or death was 340 days for those treated with decitabine, compared to 219 days for those treated with supportive care only, virtually all the patients treated with the drug showed improved health status, lower fatigue levels, ability to breathe better, and an overall increase in their quality of life.

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